Conventional incandescent and fluorescent light fittings are being replaced by more energy efficient and more environmentally friendly light emitting diode (LED) light fittings.
Conventional light fittings comprise a housing to contain the incandescent or fluorescent light source. The housing has an aperture through which light emitted by the light source is directed. One or more reflectors may be provided to direct light through the aperture. A light diffuser may be provided which covers the aperture and helps to diffuse (i.e. scatter) the light which passes therethrough.
Many LED light fittings mimic the previous conventional light fittings—as these are proven designs and are in demand.
However, LEDs emit a far narrower beam of light than conventional light sources (which might generally be considered to be omni-directional light sources). A conventional T5 fluorescent light source emitting light (e.g. light rays 12) in an omni-directional manner is shown in FIG. 9.
In addition, each LED typically emits far less light than a single conventional light source. Therefore, an array of LEDs is usually required to provide sufficient light over the required region.
However, when LEDs (or an array of LEDs) are used as the light sources in otherwise conventional light fittings, the light emitted by the LEDs is not sufficiently diffused to provide uniform or substantially uniform light emission across the aperture of the fitting. Instead, the location of each individual LED is typically identifiable as a bright spot of light.
The provision of a diffuser which diffuses the emitted light to a greater extent also reflects more light back into the fitting—so less light leaves the light fitting. This is therefore not an adequate solution to the problem.
Light guide boards (LGB) can be used in the light fitting in an attempt to provide uniform or substantially uniform light emission across the aperture of the light fitting. However adding additional components such as an LGB and/or a diffuser to a light fitting will increase the bulkiness (e.g. thickness) of the light fitting. In situations where the light fitting is intended to be hidden substantially away when installed or where the light fitting is intended to be installed in an area where space is at a premium, such as, under a cabinet or under a shelf, it is desirable to minimize the bulkiness of the light fitting.
The present invention seeks to ameliorate one or more problems associated with the prior art.